Method of manufacturing thin film and thin film capacitor

ABSTRACT

In a method of manufacturing a thin film, a buffer layer is formed a substrate. Thereafter, a ferroelectric thin film material is applied thereto before thermally decomposing the buffer layer. Subsequently, the buffer layer and the ferroelectric thin film are decomposed together. Finally, a crystallized thermal process is performed.

BACKGROUND OF THE INVENTION

This invention relates to a method of manufacturing a crystallized thinfilm formed by ferroelectric substance, such as Pb (Zr, Ti) O₃ (PZT) bythe use of a sol-gel method.

When a ferroelectric thin film is used as a capacitor insulating film ofa non-volatile memory, it is indispensable to reduce an area of a memorycell in order to improve the integration of the memory.

To this end, it is necessary to directly form the ferroelectric thinfilm capacitor on a conductive plug which is recently applied to a DRAM(Dynamic Random Access Memory) having high integration.

In this event, when a thermal treatment is performed during a productionof the ferroelectric thin film capacitor, the conductive plug and adiffusion barrier layer attached thereto (for example, TiN/Ti) areoxidized. Consequently, the conductivity is often and inevitably lost.

Therefore, it is required that a temperature during the production ofthe ferroelectric thin film is reduced to 500° C. or less, morepreferably 450° C. or less, to avoid such oxidation.

Meanwhile, it is well known that Pb base ferroelectric substance, inparticular, Pb (Zr, Ti) O₃ (hereinafter, abbreviated as PZT) andmaterial added slight of additive such as La and Nb into PZT is suitableas ferroelectric thin film material for the non-volatile memory. This isbecause the Pb base ferroelectric substance has a large residualpolarization, and can be produced at about 600° C.

As the production method of the ferroelectric thin film, the sol-gelmethod is desirable because it has such advantage that an excellent thinfilm can be obtained with superior repeatability using a cheaperequipment. In such a sol-gel method, an organic metal material isdissolved into desired solvent, and is applied and baked.

For example, it has been reported that PZT of Zr/Ti=53/47 becomes asingle perovskite phase by using a buffer layer of PbTiO₃ (hereinafter,abbreviated as PT) by the sol-gel method at 500° C. written in Journalof material research 1993, Vol. 8. Page 339 (C. K. K wok et al., J.Mater. Res. 8, 339 (1993)).

In this case, the production process of the PZT thin film is illustratedin FIG. 1, and the PT layer is crystallized before applying PZT. In thispaper, although a sapphire substrate is used, the electricalcharacteristic such as ferroelectric characteristic is not reported atall.

Further, disclosure has been made about such a fact that PZT is producedusing a PT buffer layer by the sol-gel method at 450° C. in JapaneseJournal of Appl. Phys, 1996, Vol. 35, page 4896 (H. Suzuki et al., Jpn.J. Appl. Phys. 35, 4896 (1996)).

Although the single perovskite phase is formed 450° C. ,as illustratedin FIG. 4 in this paper, the paper does not disclose or teach theferroelectric characteristic.

Moreover, the dielectric constant is 30 or less at about 0.2 μm, asshown in FIG. 5 in this paper, and the characteristic is not enough tobe practically used.

The process for producing the PZT thin film disclosed in this paper isillustrated in FIG. 2, and the PT layer is decomposed by an organicthermal process at 350° C. before applying PZT.

As mentioned above, the Pb base ferroelectric substance, in particular,the PZT based ferroelectric thin film (the film thickness of 300 nm orless) having excellent composition at 500° C. or less, more desirably450° C. or less has not been realized by the use of the sol-gel method

SUMMARY OF THE INVENTION

It is therefore an object of this invention to provide a method ofmanufacturing a thin film and a capacitor using excellent PZT baseferroelectric material at a low temperature by the use of the sol-gelmethod.

In a method of manufacturing a thin film according to this invention, abuffer layer is formed on a substrate. Thereafter, a ferroelectric thinfilm material is applied thereto before thermally decomposing the bufferlayer.

Subsequently, the buffer layer and the ferroelectric thin film aredecomposed together. Finally, a crystallized thermal process isperformed.

In this event, the buffer layer is provided so as to proceed thecrystallization of the thin film on the buffer layer, and may bereferred to as a seed forming layer.

The deposition temperature due to the sol-gel method can be lowered byforming the thin film using such a method.

When this method is applied to the PZT thin film, a buffer layercontaining PbTiO₃ as main component is formed on the substrate.

Thereafter, a thin film material containing PZT as main component isapplied before decomposing the buffer layer by a thermal organicprocess.

After the buffer layer and the thin film are decomposed together by thethermal organic process, a crystallized thermal process is performed.

More specifically, after the buffer layer containing PbTiO₃ as maincomponent is formed on the substrate, the buffer layer is baked at atemperature at which organic thermal decomposition does not occur.

Subsequently, a thin film material containing PZT as main component isapplied on the buffer layer.

After the PZT thin film is baked at a temperature at which the organicthermal decomposition does not occur, the buffer layer and the thin filmare decomposed together by the thermal organic process. Finally, thecrystallized thermal process is performed.

In this case, the application step of the thin film containing PZT asmain component through the crystallized thermal step may be repeatedafter the crystallized thermal process such that the PZT thin film hasthe preselected film thickness.

In this event, the duration of the final crystallized thermal processmay be longer than that of the previous crystallization thermal process.

This reason will be explained hereinbelow. Namely, when thecrystallization is carried out at such a low temperature, as thermalprocess duration is longer, the characteristic such as the ferroelectriccharacteristic is more improved.

If the crystallization thermal process is performed for long duration atevery application layers, the final crystallization thermal process isunnecessary.

However, long duration is required to manufacture the thin film when theapplication number is particularly increased. In consequence, thethroughput is degraded.

In the meantime, the layer, which is initially applied, is subjected tothe thermal process having the longest duration. Consequently, thecrystallized thermal process durations are variable for the respectiveapplication layers, and the thin film may be formed such that eachapplication layer has not a uniform characteristic.

To this end, it is preferable that the final crystallization thermalprocess, which is entirely performed, is carried out for longerduration.

Further, in a method of manufacturing a PZT thin film according to thisinvention, a buffer layer containing PbTiO₃ as main component is formedon the substrate.

Thereafter, the buffer layer is baked at a temperature at which theorganic thermal decomposition does not occur.

Subsequently, the thin film material containing PZT as main component isapplied on the buffer layer.

After the PZT thin film is baked at a temperature at which the organicthermal decomposition does not occur, the buffer layer and the thin filmare decomposed together by the thermal organic process. Finally, thecrystallized thermal process is entirely performed.

In this case, the application step of the thin film containing PZT asmain component through the thermal decomposition step may be repeatedafter the crystallized thermal process such that the PZT thin film hasthe preselected film thickness.

Further, RTA (Rapid Thermal Annealing) decomposition may be performedafter decomposing by the organic thermal process.

Alternatively, the RTA decomposition may be carried out instead of theorganic thermal decomposition.

The general organic thermal decomposition is carried out within thetemperature range between 300° C. and 400° C. for process duration ofabout 10 minutes in the oxygen atmosphere (in oxygen gas or in H₂O/O₂atmosphere).

However, the RTA decomposition is conducted at a slightly highertemperature although the process atmosphere is not changed.

Namely, the RTA is carried out within the temperature range between 430°C. and 450° C. during several seconds to several minutes, morespecifically, for about 15 seconds to about 2 minutes.

In case that the crystallization is carried out after performing the PZTapplication for several times, carbon in the film is not sufficientlydecomposed and may be remained in the film as impurity when theapplication is performed again after conducting only the general organicthermal decomposition.

Therefore, it is preferable to combine the RTA decomposition after thegeneral organic thermal decomposition.

When the crystallization thermal process temperature exceeds 500° C. inthe above-mentioned manufacturing method of the PZT thin film, thecrystallization of the perovskite phase starts without the PT bufferlayer, and the effect of the PT buffer layer is reduced. Therefore, thetemperature range between about 430° C. and 450° C. is desirable.

The thermal process temperature is variable in dependence upon thecomposition ratio between Zr and Ti in PZT. As the ratio of Ti ishigher, the perovskite phase is readily generated at the lowertemperature.

As the crystallization thermal process temperature is lower, thepyrochlore phase, which does not represent the ferrroelectriccharacteristic, is more easily generated. This phenomenon is well knownin the art.

However, it is possible to obtain the crystallized phase of theperovskite phase at the temperature of 430° C. or higher according tothis invention.

Further, the baking process is prepared in addition to thecrystallization or the organic thermal decomposition. The baking processis carried out to dry solvent, and can dry the thin film by performingthe thermal process in the desired atmosphere without the organicthermal decomposing within the temperature range between about 100° C.and 250° C. for about 10 minutes although a slight change occurs inaccordance with the kind of the solvent.

Moreover, this invention is applicable as a method of manufacturing acapacitor using the PZT thin film. In this case, an upper electrode maybe formed after crystallizing the PZT thin film.

Preferably, it is possible to obtain the ferroelectric thin filmsuperior in performance by crystallizing the PT thin film with the PZTthin film together after forming the upper portion electrode.

Further, it is preferable that the film thickness of the buffer layercontaining PbTiO₃ as main component is thinner taking the performance ofthe obtained capacitor into account. However, it is permitted that thethickness is 10% or less of the film thickness of the layer containingPZT as main component.

In FIG. 3A, the upper electrode is formed after crystallizing the PZTthin film.

Although the pervskite phase serving as the ferroelectric phase iscrystallized at 450° C. or less in PT, PT itself is not suitable as thecapacitor for the memory because anti-electric field is large and therepeating operation resistance is also small.

However, PT has such a characteristic that the crystallization iscarried out at the lower temperature and the PT is similar with PZT inthe crystal structure and the lattice constant.

With this characteristic, the energy for crystallizing PZT can bereduced by using it as the buffer layer during the deposition of PZT.

Such an effect results in the following mechanism. Namely, when thelaminated PT layer and PZT layer in the non-crystallized state aresubjected to the thermal process, the PT layer having small energy forcrystallizing is first crystallized, and the PZT layer is successivelycrystallized.

Such continuous crystallization readily proceeds when the interfacebetween the PT layer and the PZT layer has a certain degree of slope bymutual diffusion.

Therefore, the reduction effect of the PZT crystallization temperatureof the PT buffer layer is most effectively obtained when a certaindegree of mutual diffusion occurs at the interface between PZT and PT atthe stage before crystallization of PZ, and PZT and PT in thenon-crystallized state are crystallized together.

To obtain such a state, it is effective to apply the PZT layer beforeperforming the organic thermal decomposition of the PT buffer layer andconducting the organic thermal decomposition for the both together inthe sol-gel method. This is because the entire organic thermaldeposition process causes the mutual diffusion of the interface ofPZT/PT.

The continuous crystallization from the buffer layer side proceeds byperforming the crystallized thermal process in this state, and thecrystallization of PZT becomes possible at the low temperature betweenabout 430° C. and 450° C.

In FIG. 3B, the PT thin film and the PZT thin film are crystallizedafter forming the upper electrode. In this method, it is possible toimprove the polarization switching characteristic of the ferroelectricthin film capacitor formed at the low temperature between about 430° C.and 450° C. at low electric field.

The upper electrode is formed before the crystallized thermal process.Thereby, the stress inside the PZT thin film generated during thecrystallization is reduced by clamping the upper interface of the PZTthin film before the crystallization.

Further, defects generated at the interface is reduced by thermallyprocessing the interface between PZT and the upper electrode at the sametime as the PZT crystallization.

As a result, the polarization conversion characteristic of the PZT thinfilm capacitor formed under the low temperature can be improved at thelow electric field.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a flowchart showing a crystallized process of a PZT thin filmaccording to a first conventional method;

FIG. 2 is a flowchart showing a crystallized process of a PZT thin filmaccording to a second conventional method;

FIGS. 3A and 3B are flowcharts showing crystallized process of a PZTthin film according to this invention;

FIG. 4 is a diagram showing X-ray diffraction of PZT-1-4 according to afirst example;

FIG. 5 is a diagram showing a hysteresis curve of PZT-1-3 when ±5V isapplied according to a first example;

FIG. 6 is a diagram showing a hysteresis curve of PZT-5 an d PZT-6 when±5V is applied according to a second example; and

FIG. 7 is a diagram showing a hysteresis curve of PZT-1 and PZT-5 when±3V is applied.

DESCRIPTION OF PREFERRED EMBODIMENTS FIRST EXAMPLE

Description will be made about a first example of this invention below.

A thermal oxide Si substrate, which was deposited with the PT thin film(a lower electrode), was used as the ferroelectrical depositionsubstrate.

The PT buffer layer was formed by mixing anhydride lead acetate (Pb(OCOCH₃)₂) with tetra-isopropoxy titanium (Ti (OC₃H₇)₄) such that Pb/Tiwas equal to 1.15/1.00, and thereafter, dissolving into1-methoxy-2-propanol ,and was applied with 2000 rpm by the use of aspin-coater using solution adjusted to 0.03 mol/Kg.

The PT buffer layer was baked at 250° C. for 10 minutes in the air.

Subsequently, the PT buffer layer was formed by mixing anhydride leadacetate (Pb (OCOCH₃)₂) with tetra-isopropoxy titanium (Ti (O-i-C₃H₇)₄),and tetra-tert-butoxy zirconium (Zr (O-t-C₄H₉)₄) such that Pb/Zr/Ti wasequal to 1.15/0.45/0.65, and thereafter, dissolving into1-methoxy-2-propanol, and was applied with 2000 rpm by the use of thespin-coater using solution adjusted to 0.4 mol/Kg onto the substrate inwhich the PT was applied.

After the PT buffer layer was baked at 250° C. for 10 minutes in theair, the organic thermal decomposition was carried out at 400° C. for 10minutes in oxygen, and further, the first crystallization was performedat 450° C. for 10 minutes in oxygen.

The step from the PZT layer application to the first crystallization at450° C. was once repeated. Finally, the second crystallization wascarried out at 450° C. for 30 minutes in oxygen to obtain the PZT thinfilm (thereinafter, referred to as PZT-1) having the film thickness of200 nm.

In the above-mentioned process, the PZT layer was applied and bakedtwice. The first layer PZT was crystallized by the first crystallizationbefore the PZT application step of the second layer. The crystallizedfirst layer PZT served to assist the crystallization of the second layerPZT.

Consequently, the PT layer was not always applied again before applyingthe second layer PZT layer. However, the PT layer might be applied inaccordance with the ferroelectric characteristic of the obtained deviceas needed.

The PZT thin film (hereinafter, referred to as PZT-4) manufactured bythe same process without applying the PT buffer layer had the filmthickness of 185 nm. In consequence, the film thickness of the PT bufferlayer was equal to about 15 nm.

In the process of PZT-1, the PZT thin film (hereinafter, referred to asPZT-2) and the PZT thin film (hereinafter, referred to as PZT-3) weresimultaneously manufactured.

In this case, the PZT-2 was obtained by decomposing by the organicthermal process at 400° C. for 10 minutes in oxygen successively afterbaking the PT buffer layer at 250° C.

On the other hand, the PZT-3 was obtained by crystallizing at 450° C.for 10 minutes in oxygen successively after baking the PT buffer layerat 250° C.

The PZT-2 corresponded to a sample when the PT buffer layer wasdecomposed by the organic thermal process before applying the PZT layer.While, the PZT-3 corresponded to a sample when the PT buffer layer wascrystallized before applying the PZT layer.

In this event, the X-ray diffraction of PZT-1-4 are illustrated in FIG.4.

In the PZT thin film having no PT buffer layer, the pyrochlore phase ofthe normal dielectric phase appeared. By contrast, the perovskite phasewas crystallized in the PZT thin film on the PT buffer layer.

It is apparent that the PT buffer layer had an effect for reducing thecrystallized temperature of PZT on the PT buffer layer.

However, each of the PZT-2 and the PZT-3 had the low intensity of theperovskite phase and the mixed pyrochlore phase, and low crystallizeddegree of the perovskite phase in comparison with the PZT-1 in which thePT buffer layer and the PZT layer were decomposed together by theorganic thermal process and were crystallized together.

When the surfaces of the PZT-1-4 were observed by the use of theelectron microscope, perovskite crystal grains were closely generatedwithin the range of about 0.1-0.3 μm.

By contrast, island-like perovskite crystal grains existed with lowdensity in PZT-2 and PZT-3, and the remaining portion was buried withpyrochlore microcrystalline grains. In PZT-4, the perovskite crystalgrains were not observed at all.

An Ir/IrO₂ upper portion electrode having a diameter of 300 μm wasformed on the surface of PZT-1-3 by the use of the magnetron-sputteringmethod, and was annealed at 450° C. in oxygen.

The hysteresis curve when ±5 V was applied is illustrated in FIG. 5.

PZT-1 represents the ferroelectric hysteresis, and the differencebetween the positive remanent polarization and the negative remanentpolarization was 2Pr=30.5 μC/cm². In contrast, each of PZT-2 and PZT-3did not represent the ferroelectric characteristic.

In this event, the polarization fatigue phenomenon due to the repetitiondue to the polarization reversal was measured by continuously applyingbipolar pulses of ±5 V with respect to PZT-1, it was confirmed that thereduction of the remanent polarization was not observed until 10⁸ cycle.

From the above-mentioned results, it was apparent that it was effectiveto decompose by the organic thermal process and crystallize for thelaminated PT buffer layer and PZT layer together when the PZT thin filmwas crystallized at 450° C.

Although the PZT layer was applied and baked twice in the first example,the application number could be suitably and freely changed independence upon the film thickness.

SECOND EXAMPLE

Description will be made about a second example of this invention below.

The PT layer was first applied on the substrate by the use of the spincoater with 2000 rpm using the same substrate, the solution for the PTbuffer layer and the solution for the PZT layer, and was baked at 250°C. for 10 minutes in oxygen.

Subsequently, the same solution for the PZT layer as the first examplewas applied onto the substrate applied with the PT by the use of thespin coater with 2000 rpm.

After the solution was baked at 250° C. for 10 minutes in the air, theorganic thermal decomposition was carried out at 400° C. for 10 minutesin oxygen ,and further, the rapid thermal anneal (RTA) was conducted at450° C. for 30 seconds in oxygen.

The step from the PZT layer application to the RTA at 450° C. in oxygenwas repeated once to obtain the PZT thin film having the film thicknessof 200 nm. It was confirmed that the PZT layer was not crystallized tothe perovskite phase in this stage.

The RTA process was carried out in order to perform complete organicthermal decomposition at a higher temperature than 400° C. by performingthe oxygen process of 450° C. for a short duration without crystallizingPZT to the perovskite phase.

The Ir/IrO₂ upper electrode having the diameter of 300 μm was formed onthe surface of the obtained PZT thin film by the use of themagnetron-sputtering method, and the crystallization thermal process wasfinally conducted at 450° C. for 30 minutes in oxygen to obtain a PZTthin film capacitor (hereinafter, referred to as PZT-5).

As a comparative example, after the crystallized thermal process wascarried out at 450° C. for 30 minutes in oxygen before the formation ofthe upper electrode in the process of this example, the Ir/lrO₂ upperelectrode was formed to obtain a PZT thin film capacitor (hereinafter,referred to as PZT-6).

The hysteresis curves of PZT-5 and PZT-6 when ±5 V was applied areillustrated in FIG. 6.

PZT-6, in which the upper electrode was manufactured after thecrystallization, did not have the ferroelectric ;characteristic. Bycontrast, PZT-5, which was crystallized after forming the upperelectrode, represents rectangular excellent hysteresis characteristic,and 2Pr=26.8 μC/cm² was obtained.

Further, the hysteresis curves of PZT-1 and PZT-5 when ±3 V was appliedare illustrated in FIG. 7.

It was found out that PZT-5 had higher rectangular hysteresischaracteristic, and was sufficiently saturated at 3V. Further, 2Pr ofPZT-1 was equal to 16.8 μC/cm ² at 3V while 2Pr of PZT-5 was equal to23.7 μC/cm² at 3V, and PZT-5 had a higher remanent polarization value.

In this event, the polarization fatigue phenomenon due to the repetitiondue to the polarization reversal was measured by continuously applyingbipolar pulses of ±5 V with respect to PZT-1, it was confirmed that thereduction of the remanent polarization was not observed until 10⁸ cycle.

From the above-mentioned results, it is apparent that the appearance ofthe ferroelectric characteristic is proceeded by performing thecrystallized thermal process after forming the upper electrode beforecrystallizing to the perovskite phase of PZT when the PZT thin film iscrystallized at 450° C.

Thereby, the PZT thin film capacitor, which is superior in thepolarization conversion characteristic under low electric field, can beobtained.

In the above-mentioned embodiment, PZT of Zr/Ti=35/65 was used as theferroelectric thin film while PT was used as the buffer layer.

When PZT different from Zr/Ti or PZT based donor additive, such as, Laand Nb, or acceptor additive, or additive, such as, Ca and Sr forimproving electric characteristic was added with about several mol % incomposition as the ferroelectric thin film, the absolute value of thecrystallized temperature was slightly changed. However, the effect ofthis invention was not changed.

Similarly, this invention is effective for the composition in which thesame additive is added with about several mol % using PT serving as thebuffer layer as the base.

When the thin film application is carried out several times, althoughthe application is performed by the use of the same material, thematerial having different composition (for example, Zr/Ti ratio) oradditive content may be used.

Further, this invention is not readily affected by the bottom electrodematerial because PZT is crystallized via the buffer layer.

Consequently, this invention is sufficiently effective for the bottomelectrode material other than PT, such as, Ir, IrO₂, Ru and RuO₂, andthe other conductive oxide electrode.

As the upper electrode, when the crystallization is particularlyconducted after forming the upper electrode, the materials, such as Ir,IrO₂, Ru, and RuO₂, which can keep the conductivity in the oxideatmosphere, can be used.

However, the material is particularly restricted in the invention, andthe other conductive oxide electrode may be used.

As mentioned above, the thin film, which has large remanent polarizationat the low temperature and small polarization fatigue, can be obtainedby using the sol-gel method in which the excellent thin film can beobtained with good repeatability using the cheaper equipment accordingto this invention.

Further, the capacitor, which superior in the polarization switchingcharacteristic in the low electric field, can be also obtained.

In particular, according to this invention, the PZT thin film can beformed by the sol-gel method at the low temperature of about 430° C.which is impossible in the conventional method.

In consequence, the conductivity is not lost or eliminated by theoxidation of the conductive plug or the diffusion barrier layer. As aresult, the device having high reliability can be realized.

While this invention has so far been disclosed in conjunction withseveral embodiments or examples thereof, it will be readily possible forthose skilled in the art to put this invention into in various othermanners.

What is claimed is:
 1. A method of manufacturing a thin film on asubstrate, comprising the following sequential steps of: forming abuffer layer on the substrate; applying a ferrocelectric thin filmmaterial before performing a first thermal decomposition of the bufferlayer; performing said first thermal decomposition of the buffer layerand the ferroelectric thin film together; and performing acrystallization thermal process.
 2. A method of manufacturing a PZT thinfilm on a substrate, comprising the following sequential steps of:forming a buffer layer containing PbTiO₃ as main component on thesubstrate; applying a thin film material containing PZT as maincomponent before performing a first organic thermal decomposition of thebuffer layer; and performing said first organic thermal decomposition ofthe buffer layer and the thin film together; and performing acrystallization thermal process.
 3. A method of manufacturing a PZT thinfilm on a substrate comprising the following sequential steps of:forming a buffer layer containing PbTiO₃ as main component on thesubstrate; baking the buffer layer at a temperature at which organicthermal decomposition does not occur; applying a thin film materialcontaining PZT as main component on the buffer layer; baking the PZTthin film at a temperature at which the organic thermal decompositiondoes not occur; performing a first organic thermal decomposition of thebuffer layer and the thin film together; and performing acrystallization thermal process.
 4. A method as claimed in claim 3,further comprising the steps of: applying the thin film material againafter performing the crystallization thermal process; baking the PZTlayer at a temperature at which the organic thermal decomposition doesnot occur; and performing the crystallization thermal process afterperforming said organic thermal decomposition of the buffer layer,wherein these steps being repeated such that the PZT thin film has thepreselected film thickness.
 5. A method as claimed in claim 4, wherein:the crystallization thermal process after the PZT thin film has apreselected thickness is carried out during a first duration, and thecrystallization thermal process is previously carried out during asecond duration, the first duration being longer the second duration. 6.A method as claimed in claim 3, further comprising the following stepof: performing a RTA thermal decomposition after performing said organicthermal decomposition of the buffer layer.
 7. A method as claimed inclaim 3, wherein: a RTA thermal decomposition is carried out instead ofthe organic thermal decomposition.
 8. A method as claimed in any one ofclaims 3, 6 or 7 further comprising the steps of: applying the thin filmmaterial again after performing the crystallization thermal process;baking the PZT thin film at a temperature at which the organic thermaldecomposition does not occur; repeating the organic thermaldecomposition such that the PZT thin film has the preselected filmthickness; and performing the crystallization thermal process.
 9. Amethod as claim in any one of claims 2 to 8, wherein: thecrystallization thermal process is carried out within the range between430° C. and 500° C.
 10. A method of manufacturing a thin film capacitoron a bottom electrode, comprising the following sequential steps of:forming a buffer layer on the bottom portion electrode; applying aferroelectric thin film material before performing a first thermaldecomposition of the buffer layer; performing said first thermaldecomposition of the buffer layer and the ferroelectric thin filmtogether; and performing a crystallization thermal process.
 11. A methodof manufacturing a PZT thin film capacitor on a bottom electrode,comprising the following sequential steps of: forming a buffer layercontaining PbTiO₃ as main component on the bottom electrode; applying athin film material containing PZT as main component before performing afirst organic thermal decomposition of the buffer layer; and performinga said first organic thermal decomposition of the buffer layer and thethin film together; and performing a crystallization thermal process.12. A method of manufacturing a PZT thin film capacitor on a bottomelectrode, comprising the following sequential steps of: forming abuffer layer containing PbTiO₃ as main component on the bottomelectrode; baking the buffer at a temperature at which organic thermaldecomposition does not occur; applying a thin film material containingPZT as main component on the buffer layer; baking the PZT thin film at atemperature at which the organic thermal decomposition does not occur;performing a first organic thermal decomposition of the buffer layer andthe thin film together; performing a crystallization thermal process;and forming an upper electrode.
 13. A method as claimed in claim 12,further comprising the steps of: applying the thin film material againafter performing the crystallization thermal process; baking the PZTlayer at a temperature at which the organic thermal decomposition doesnot occur; and performing the crystallization thermal process afterperforming said organic thermal decomposition of the buffer layer, thesesteps being repeated such that the PZT thin film has the preselectedfilm thickness.
 14. A method as claimed in claim 13, wherein: thecrystallization thermal process after the PZT thin film has thepreselected thickness is carried out during a first duration, and thecrystallization thermal process is previously carried out during asecond duration, the first duration being longer the second duration.15. A method of manufacturing a PZT thin film capacitor on a bottomelectrode, comprising the following sequential steps of: forming abuffer layer containing PbTiO₃ as main component on the bottomelectrode; baking the buffer layer at a temperature at which a firstorganic thermal decomposition does not occur; applying a thin filmmaterial containing PZT as main component on the buffer layer; bakingthe PZT thin film at a temperature at which said organic thermaldecomposition does not occur; performing said first organic thermaldecomposition of the buffer layer and the thin film together; andentirely performing a crystallization thermal process.
 16. A method asclaimed in claim 15, further comprising the following steps of:performing a RTA thermal decomposition after performing said organicthermal decomposition of the buffer layer.
 17. A method as claimed inclaim 15, wherein: a RTA thermal decomposition is carried out instead ofthe organic thermal decomposition.
 18. A method as claimed in any one ofclaim 15 to 17, further comprising the steps of: applying the thin filmmaterial again after performing the crystallization thermal process;baking the buffer layer at a temperature at which the organic thermaldecomposition does not occur; repeating the organic thermaldecomposition such that the PZT thin film has the preselected filmthickness; and performing the crystallization thermal process.
 19. Amethod as claimed in any one of claims 15 to 18, further comprising thefollowing steps of: forming the upper electrode before thecrystallization thermal process.
 20. A method as in any one of claims 10to 19, wherein: the crystallization thermal process is carried outwithin the range between 430° C. and 500° C.